When it comes to finding life on other planets, so far the score stands at Earth 1, Universe 0. It’s certainly not been for lack of trying. Over the past few decades NASA has launched a wide range of exploratory vehicles, from rovers like Curiosity to probes like Cassini. We’ve learned a tremendous amount about the planets, moons, and other bodies of the solar system as a result. At the same time, telescopes like Kepler have demonstrated the stars of the Milky Way galaxy commonly have planets, including planets of approximate Earth size that sit in the habitable zone of their stars, and might be capable of retaining liquid water on their surfaces.